640 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



Among the useful Umbelliferae are garden vegetables, such as carrot, 

 parsnip, celery, and parsley, and condiment plants, such as caraway, 

 fennel, dill, anise, and coriander. On the other hand, some of these 

 plants are very poisonous, notably the waterhemlocks (Cicuta spp.) 

 and poisonhemlock (Conium maculatum) . The latter, an Old World 

 plant, is" extensively naturalized in the United States but has not 

 been reported from Arizona. 



Key to the genera 



1. Inflorescence capitate, not umbellate (2). 



2. Fruit not winged, ribless, variously squamose 3. Eryngium. 



2. Fruit winged, not squamose 22. C ymopterus. 



1. Inflorescence a distinct umbel, more or less spreading, never capitate (3). 



3. Leaves simple; umbels simple or proliferous (4). 



4. Ovary and fruit covered with stellate hairs; foliage more or less stellate- 

 pubescent 2. Bowlesia. 



4. Ovary and fruit glabrous; foliage glabrous (5). 



5. Leaves with a definite ovate to orbicular blade 1. Hydrocotyle. 



5. Leaves reduced to hollow cylindric jointed petioles. 15. Lilaeopsis. 

 3. Leaves variously compound; umbels compound or rarely simple by reduc- 

 tion (6). 

 6. Ovary and fruit armed with bristles, callous teeth, or papillae (7). 



7. Ovary and fruit linear or linear-oblong, several times longer than wide; 



oil tubes absent or obscure in mature fruit 4. Osmorhiz a. 



7. Ovary and fruit ovate to oblong, not more than twice as long as wide; 



oil tubes present in mature fruit (8). 



8. Stems and leaves variously hispid; involucre foliaceous; bractlets 



of the involucel foliaceous, usually p innately divided; fruit 



armed with barbed or hooked bristles (9) . 



9. Fruit flattened laterally, the bristles hooked, not barbed; stylopo- 



dium conic; calyx teeth prominent 5. Caucalis. 



9. Fruit flattened dorsally, the bristles barbed at tip; stylopodium 



absent; calyx teeth absent 29. Daucus. 



8. Stems and leaves glabrous or somewhat roughened, never hispid; 

 involucre mostly absent; bractlets of the involucel linear or fili- 

 form and entire, or absent; fruit armed with short bristles, callous 

 teeth, or papillae (10). 



10. Involucel absent; umbels sessile; fruit papillate-. 7. Apiastrum. 

 10. Involucel present; umbels peduncled; fruit not papillate (11). 



11. Fruit covered with short bristles; seed face more or less sulcate. 



9. Spermolepis. 

 11. Fruit covered with callous teeth; seed face plane to somewhat 



concave 10. Ammoselinum. 



6. Ovary and fruit not armed, sometimes pubescent (12). 



12. Ribs of the fruit not prominently winged, the ovary and fruit terete in 

 cross section or somewhat flattened laterally (13). 

 13. Petals conspicuously unequal; fruit subglobose, not constricted at 



the commissure 6. Coriandrum. 



13. Petals equal; fruit orbicular to oblong, more or less constricted at 

 the commissure (14). 

 14. Flowers yellow; plants with an aniselike odor_ 16. Foentculum. 

 14. Flowers not yellow; plants without an aniselike odor (15). 

 15. Ribs of the fruit corky; plants of marshes or aquatic (16). 

 16. Involucre inconspicuous or absent; some or all of the leaves 



ternate-pinnate 11. Cicuta. 



16. Involucre conspicuous; leaves simply pinnate (17). 

 17. Ribs of the fruit corky, equal; stylopodium depressed. 



13. Sium. 

 17. Ribs filiform, the pericarp forming a continuous corky 



covering; stylopodium conic 14. Berula. 



15. Ribs of the fruit not corky; plants of dry ground or moist 

 meadows (18). 

 18. Ribs narrowly winged; leaflets variously incised. 



18. Ligusticum. 



